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The periosteum is a membrane that covers the outer surface of all bones, [1] except at the articular surfaces (i.e. the parts within a joint space) of long bones. (At the joints of long bones the bone's outer surface is lined with "articular cartilage", a type of hyaline cartilage.)
Active transport is used to move most substances between the blood vessels and the osteocytes. [1] Haversian canals are contained within osteons, which are typically arranged along the long axis of the bone in parallel to the surface. The canals and the surrounding lamellae (8-15) form the functional unit, called a Haversian system, or osteon.
The Haversian canal contains the bone's blood supplies. The boundary of an osteon is the cement line. Each Haversian canal is surrounded by varying number (5-20) of concentrically arranged lamellae of bone matrix. Near the surface of the compact bone, the lamellae are arranged parallel to the surface; these are called circumferential lamellae.
The outer surface of a bone is lined by a thin layer of connective tissue that is very similar in morphology and function to endosteum. It is called the periosteum, or the periosteal surface. During bone growth, the width of the bone increases as osteoblasts lay new bone tissue at the periosteum.
This is covered by a membrane of connective tissue called the periosteum. Beneath the cortical bone layer is a layer of spongy cancellous bone. Inside this is the medullary cavity which has an inner core of bone marrow, it contains nutrients and help in formation of cells, made up of yellow marrow in the adult and red marrow in the child.
The nutrient canal (foramen) is directed away from the growing end of bone. The growing ends of bones in upper limb are upper end of humerus and lower ends of radius and ulna. In lower limb, the lower end of femur and upper end of tibia are the growing ends. [1] The nutrient arteries along with nutrient veins pass through this canal.
Because of their rich blood supply and vascular stasis, metaphyses of long bones are prone to hematogenous spread of osteomyelitis in children. [ 4 ] Metaphyseal tumors or lesions include osteosarcoma , chondrosarcoma , fibrosarcoma , osteoblastoma , enchondroma , fibrous dysplasia , simple bone cyst , aneurysmal bone cyst , non-ossifying ...
The inner layer, tunica intima, is the thinnest layer. It is a single layer of flat cells (simple squamous epithelium) glued by a polysaccharide intercellular matrix, surrounded by a thin layer of subendothelial connective tissue interlaced with a number of circularly arranged elastic bands called the internal elastic lamina. A thin membrane of ...